Cardiac rhythm management systems are useful for electrically stimulating a patient's heart to treat various cardiac arrhythmias. A proposed method of electrically stimulating the heart includes stimulating the bundle of His. By directly stimulating the bundle of His, both the right and left ventricles can be physiologically activated, potentially avoiding pacing induced dyssynchrony present with right ventricular apex pacing. There is a continuing need for improved delivery systems for targeting the bundle of His.